1. Field
Example embodiments of the present invention relate to an organic insulator composition, an organic insulating film having the organic insulator composition, an organic thin film transistor having the organic insulator composition, an electronic device having the organic thin film transistor and methods of forming the same. Other example embodiments of the present invention relate to an organic insulator composition including a fluorinated silane compound that may be used to improve the charge carrier mobility and hysteresis of an organic thin film transistor.
2. Description of the Related Art
Flat panel displays (e.g., liquid crystal displays and/or organic electroluminescence displays) may include a number of thin film transistors (TFTs) for driving the devices. Thin film transistors may include a gate electrode, a gate insulating layer, source and/or drain electrodes and a semiconductor layer activated in response to the driving of the gate electrode. Amorphous silicon (a-Si) and polycrystalline silicon (poly-Si) may be currently used as channel materials for semiconductor layers of thin film transistors (TFTs). Recent developments in various conductive organic materials have led to a great deal of research on organic thin film transistors (OTFTs) using organic semiconductor materials (e.g., pentacene, polythiophene and/or any other suitable material). OTFTs may have lower charge carrier mobility, higher driving voltage and/or higher threshold voltage when compared to transistors using amorphous Si. In order to simplify fabrication and reduce fabrication costs, OTFTs may be fabricated by an all-printing and/or all-spin process on plastic substrates. There has been research into increasing the charge carrier mobility at the interface between gate insulating layers and organic semiconductor layers and forming gate insulating layers by a simplified procedure.
According to the conventional art, a gate insulating layer may be made of an inorganic metal oxide (e.g., BaxSr1-xTiO3 (barium strontium titanate (BST)), Ta2O5, Y2O3, TiO2 and/or any other suitable inorganic metal oxide) or a ferroelectric insulator (e.g., PbZrxTi1-XO3 (PZT), Bi4Ti3O12, BaMgF4, SrBi2 (Ta1-xNbx)2O9, Ba(Zr1-xTix)O3 (BZT), BaTiO3, SrTiO3, Bi4Ti3O12 and/or any other suitable ferroelectric insulator) and may be formed by chemical vapor deposition, physical vapor deposition, sputtering, and/or sol-gel coating. Although the driving voltage of the OTFTs may be reduced to as low as about −5V, the charge carrier mobility may still be about 0.6 cm2/Vs or less. Because most fabrication processes require a relatively high temperature of about 200° C.˜about 400° C., plastic substrates suitable for use in the manufacture of flexible displays may not be used. Common wet processes (e.g., simple coating and/or printing) may not be applied to fabricate the devices. The conventional art may also suggest the use of polyimide, benzocyclobutene and photoacryls as materials for organic insulating films. The characteristics of organic insulating films formed using the materials may be insufficient to replace inorganic insulating films.